The milling machine is one of the machine tools to be used in a mechanical processing factory and the metal processing industry, and it usually uses a rotating cutter to cut metals in the milling operation. The milling machine is considered to be a multi-function machine with different kinds of cutters which are used for face milling, slot milling, hole milling or boring.
A specific cutter has to be mounted on the machine for milling a different surface.
Referring to FIG. 6, it shows a prior art vertical type of tool-replacing implement and this implement generally, comprises a reach rod A, a driving spindle B, a tool post C and a cutter D, of which the assembling and disassembling procedures are as follows:
(1) Assembling: The cutter D is first mounted, on the tool post C, being locked with nut E; the reach rod A is screwed into the screw hole on the tool post C; the key hole on the cutter D is aligned with the key F under the driving spindle B. Then, screw the nut G tightly on the top of the reach rod A with an adjustable wrench. As soon as the power supply switch is turned on, the milling operation will start. Since the screwed direction between the cutter D and the reach rod A is the same as the rotation direction of the cutter D, the cutter will have a better support and fixing means.
(2) Disassembling: To replace a cutter D, turn off the switch first, and unscrew the reach rod A with an adjustable wrench. When the reach rod A has been unscrewed and loosened, the driving spindle B and the tool post C still maintain some clamping force; therefore, knock the top portion of the reach rod A so as to have the tool post C and the driving spindle B separated from each other in order to replace the cutter D.
Although the aforesaid method may be used to replace a tool, it still has some drawbacks, in the actual operation, as follows:
1. The reach rod A is positioned high above the driving spindle B. To replace a tool, a machine operator has to climb up and stand on the working table or the like; it would be rather inconvenient for him to climb up and down. Generally, several cutters (having different sizes or for different working requirements) have to be used for making one product; in that case, more time and manpower will be required or wasted.
2. The method of replacing a tool or cutter by knocking the reach rod A to eject the tool post C is susceptible to damage of the reach rod A, and to damage of the cutter, which might be fallen down upon knocking the reach rod with one hand, while the other hand tries to hold the cutter.
3. It is rather difficult to have the cutter D and the key F of the driving spindle B exactly engaged together with the operator's hands. Since there is a larger gap between the reach rod A and the hole in the driving spindle, an eccentric rotation between the cutter D and the reach rod A might take place to jeopardize the cutting precision.